In one method of manufacture of such flexible tubes, a fitment defining a threaded neck is attached to an open-ended tube and then the product is filled through the other end of the tube and the other end is closed.
In another method of making such flexible tubes, a hollow container having an integral neck is formed, as by blow molding, the base of the container is severed from the container, the container is placed on a mandrel whereupon decoration is applied to the open-ended container, a closure is applied to the finish and then the container is filled through the open end and the open end is sealed.
Among the objectives of the present invention are to provide a flexible tube having exceptional decoration or indicia; which incorporates a finish that requires no trimming; wherein the decoration can be applied by conventional silk screening equipment; wherein decorating such as silk screen and heat transfer can be done at high speeds; and wherein closures can be applied to the flexible tubes with a higher torque and at higher speeds.
In accordance with the invention, the method of forming a flexible plastic tube comprises injection molding a finish having an opening, extruding a tube integrally with the finish by relevant movement of the finish with respect to an extruder orifice, moving the finish axially away from the extruder orifice while continuing continuously extruding the tube, closing a blow mold about the extruded tube, blowing the tube into an integral container body having a closed bottom, opening the molds to provide an integral flexible tube with a finish thereon. Thereafter the method consists of decorating the body with indicia, and cutting the closed end of the tube leaving an open-ended tube of the end opposite the finish, and applying a closure to the finish. Preferably a closure is applied before cutting the bottom from the container. Preferably the closure is applied to the finish after decorating. Subsequently, the tube is filled through the open end and the open end is sealed. The step of decorating includes rotating the tube about the longitudinal axis of the tube while engaging the finish and bottom. The step of decorating preferably comprises rotating the container relative to a silk screen printing device. The step of injection molding and extrusion molding preferably comprises injecting and extruding linear low density polyethylene. However, high density polyethylene, low density polyethylene and polypropylene may be used.
In accordance with a further aspect of the invention, a container structure is provided that facilitates handling, rotating and decorating the container before cutting the closed end. The base of the container is provided with a single diametrical lug which is engaged by the complementary lug on the rotating chuck. In a further form of the container, the body of the container is strengthened by diametrically opposed surfaces which are arcuate in horizontal cross section and taper axially downwardly and inwardly toward the base of the container. In another form of the container the entire lower end of the container is tapered axially downwardly and inwardly to form a frustoconical surface. In still further form of container, a plurality of cicumferentially spaced grooves our provided on the frusto-conical surface. In another form of container, the container is formed only with the frustoconical surface and grooves.